2. The Eyelids DR. NAILA ALI ASSISTANT PROFESSOR OPHTHALMOLOGY

3. The eyelids are movable folds which act as a shutter protecting eye from injury or excessive light.  Both the upper and lower eyelids meet at medial and lateral canthi with the opening the papebral fissure between them.

4. SURFACE ANATOMY  Superior Palpebral Sulcus  Lateral Canthus  Medial Canthus  Palpebral Fissure

5. ON THE MEDIAL SIDE  Lacus lacrimalis  Caruncula lacrimalis  Plica semilunaris

6. The medial 1/6th is distinct and it contains  papilla lacrimalis  punctum lacrimalis  canaliculus lacrimalis.

7. THE STRUCTURE The margin of each eyelid is 2mm thick and 30mm long It contains eyelashes and just posterior to it are the meibomian glands orifices. The tissues of the lids from anterior (cutancous) to posterior conjunctival aspects as follows :-  skin  subcutaneous areolar tissue  layer of striated muscle (orbicularis oculi)  sub muscular areolar tissue  layer of non striated muscle  the fibrous layer—including tarsal plate  conjunctiva

11. THE SKIN  It is thinnest and marked by sulci.  The superior sulci is due to aponeurosis of levalor palpebrae superior inserted into the skin.  The less obvious lower sulci is due to the skin being tethered to the underlying periosteum.  Histologically it consist of epidermis, sebaceous and sweat gland and melanocytes.

12. EYE LASHES  100 in upper lid  50 in lower lid  Originate from anterior lamella in two or three irregular rows.  The upper lid lashes are directed upward, and outwards  The lower lid lashed are directed downward and outwards

13. THE SUBCUTANEOUS AREOLAR TISSUE  It is a loose connective tissue containing no fat.  It is absent at medial and lateral angles, ciliary margin and at sulci.

14. THE ORIBICULARIS OCULI PartPositionFunction  Orbital Surrounds the orbital Forced lid closure rim  PreseptalIn front of the orbitalpull lacrimal fascia Septumlaterally and create a relative vacuum in lacrimal sac.  Pretarsalin front of the tarsalClose lid and pull Platelacrimal puncta medially

16. THE FIBROUS LAYER---ORBITAL SEPTUM AND TARSAL PLATE  Attached to the orbital margin.  Lies post to the medial palpebral ligament and lateral palpebral raphe medially and laterally.  With in the lids it is thickened to form tarsal plates—embedded in it are tarsal glands.

18. THE LIGAMENTS  The medial palpebral ligament attaches the medial end of tarsi to lacrimal crest and frontal process of maxilla.  The lateral palpebral ligament attach the lateral end of tarsi to margin tubercle on marginal tubercle of zygomatic bone.

19. LEVATOR PALPEBRAE SUPERIOR  Originate from lesser wing of sphenoid bone and is inserted an aponeurosis on the ant surface of superior tarsal plate, skin, lat palpebral ligament, medial palpebral ligament  From its inferior surface arises the superior tarsal muscle.

20. CONJUNCTIVA  Thin mucous membrane lined by non keratinized stratified squamous epithelium.  It has a richly vascularized Substantia propria  At the margin of the eyelids it is continuous with the skin.

21. ARTERIAL SUPPLY  The lateral palpebral Artery---lacrimal artery.  medial palpebral artery---Ophthalmic Artery.  Marginal and Peripheral arcades.

22. VENOUS DRANAGE  Medially – Ophthalmic and angular vein  Laterally-superficial temporal vein

23. NERVE SUPPLY  Upper eyelid  Supra orbital nerve  Supra trochlear nerve  Infra trochlear nerve  Lacrimal nerve  Lower eyelid  Infra trochlear nerve  Infra orbital nerve

24. LYMPHATIC DRAINAGE

25. SECRETION OF THE EYELIDS Glands Tear Film LayerLocation of glands  Meibomian glandOily layerTarsal plate  Glands of Zei’sOily layer Eyelashes  Glands of WolfringAqueous layerTarsal plate  Glands of Krause Aqueous layerFornix

26. Blinking There are two main types of blinking  Reflex blinking  Spontaneous Blinking

27. Reflex Blinking Tactile  Corneal Touch  Cortical Connection  Dimunation of sensitivity in contact lens wearer Dazzle  Bright light  Optic nerve--- Superior colliculus  Associated fiber to facial nuclei Menace  Sudden presence of near object  Optic nerve--- Cortical Connection  Predominantly cortical in nature

28. Spontaneous Blinking –Occurs at regular basis without an apparent external stimuli. –Mechanics facilitates the drainage of tear film. –Present in blind as no retinal stimuli are required.

29. Blephrospasm  Simultaneous forcible contraction of orbiculars oculi.  Forcible closure of the lids.  Its role in surgical procedures.  Anterior segment injury.

30. THANK YOU